# RPM –qa |grep sendmail

# yum install sendmail*

Package needs to be install.

 # sendmail-devel

 # sendmail-cf

 # sendmail-doc

 # vi /etc/mail/sendmail.cf 

    “ DO NOT CHANGE THIS FILE”

 # vi /etc/mail/sendmal.mc

  5 time page down

  DAEMON option

  MTA  = mail transfer agent.

dnl DAEMON options (‘port=smtp,addr=127.0.0.1, Name = MTA’) dnl

 (End of file )

  Local_DOMAIN (‘lion.com’) dnl 

# Line.com is your domain name sever

# mail –v Emailname@domain.com

Here As per config.

# mail –v rocky@lion.com    

 CTRL + D ( to stop writing in kernel)

Cc: Rambo@lion.com  (Press Enter)

#m4 sendmail.mc>sendmail.cf 

 #yum install dovecot

  # Perl-dbi

  # mysql

  # Dovecot

 # vi /etc/dovecot.conf

 protocols= imap imaps pop3 po3s

# service dovecot restart

# service sendmail restart

In the firewall ports for incoming pop (110) and outgoing (25)  needs to enable to use from networks.